One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,18)(12,20)(13,15)(14,17)(16,21)(19,23)(22,24)(25,26,31,32)(27,28,29,33)(30,38,39,34)(35,40,37,36)(1,2)(3,6)(4,7)(5,8)(9,11,14,13)(10,15,17,18)(12,19,21,22)(16,23,20,24)(26,32)(27,29)(34,38)(35,37)(1,3)(2,5)(4,8)(6,7)(25,27,31,29)(26,33,32,28)(30,35,39,37)(34,40,38,36)(1,2)(3,5)(4,7)(6,8)(9,12)(10,16)(11,19)(13,22)(14,21)(15,23)(17,20)(18,24)(25,28,31,33)(26,27,32,29)(30,36,39,40)(34,35,38,37)(1,3)(2,6)(4,8)(5,7)(9,13,14,11)(10,15,17,18)(12,19,21,22)(16,24,20,23)(25,29,31,27)(26,33,32,28)(30,37,39,35)(34,40,38,36)(1,2)(3,5)(4,7)(6,8)(9,10)(11,15)(12,16)(13,18)(14,17)(19,23)(20,21)(22,24)(25,30)(26,34)(27,35)(28,36)(29,37)(31,39)(32,38)(33,40) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.